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Author Topic: Belt drive electric motor in 70cm fishing boat  (Read 930 times)

Hurric123

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Belt drive electric motor in 70cm fishing boat
« on: December 04, 2018, 08:35:47 am »

Hi,
I have a small fishing boat, 70cm , where the electric motor has a brass gear which sits above and meshes with a similar bigger gear on the prop shaft.
There is a lot of play and noise from the gears. I have moved the motor to get a free running set up but I dont like the way the gears mesh. Also it is very hard to get the 4 screws in and out each time as the motor is not under the hatch .
I am thinking of making up a new mount which will be firmer maybe a new motor as well but I am thinking rubber belt drive?
Will this give me a nice free running set up without too much side load on the shaft?
Secondly who is the best supplier of toothed wheels and rubber drive belts.


PS do these rubber belts last or do you find them rotting and snapped like old rubber bands
Thanks guys
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canabus

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Re: Belt drive electric motor in 70cm fishing boat
« Reply #1 on: December 04, 2018, 09:43:15 am »

Hi Hurric123
I have two 850mm Hellen fishing boats which had the same problem !!!
The local hobby shop guy, said use a 540 35mm brush motor from a rock crawler.
A 55 turn or 60 turn which has very good low revs and high torque.
I have both motors and run direct drive to 60mm 3 blade brass props.
Using 7.2 volt Lipo batteries and at half throttle a bit over scale speed.
Very quiet setup.

Canabus
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Hurric123

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Re: Belt drive electric motor in 70cm fishing boat
« Reply #2 on: December 04, 2018, 02:02:14 pm »

Hi
Thanks for the info but I think my prop shaft is too low for a straight coupling connection. Dont think any motor mount will get the motor low enough ,that,s why I am thinking of a belt drive?
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grasshopper

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Re: Belt drive electric motor in 70cm fishing boat
« Reply #3 on: December 04, 2018, 04:22:22 pm »

Iíve used O rings for belts and simple pulleys on a launch for a 2:1 reduction, quiet and easy to fit - 540 motor and 7.2volts with an X40, worked okay until I upped the volts to 9.6....it started throwing the belt off then..


How big a prop are you turning and what motor is currently fitted?
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Treble

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Re: Belt drive electric motor in 70cm fishing boat
« Reply #4 on: December 04, 2018, 04:23:50 pm »

Hi Hurric  . Have you tried having a word with SHG . He is very helpful and has an on-line catalogue showing gears and belts etc . No connection  with company . Trevor .
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grasshopper

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Re: Belt drive electric motor in 70cm fishing boat
« Reply #5 on: December 04, 2018, 05:52:42 pm »

Suppliers of pulleys and toothed belts....Darnall gears, Hobby's catalogue or on-line, RS components ( expensive).



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davidm1945

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Re: Belt drive electric motor in 70cm fishing boat
« Reply #6 on: December 04, 2018, 05:59:33 pm »

Hi,  Yep, I would go along with grasshopper and use simple brass pulleys and "O" rings geared 2:1. I have used them on my 35 inch Vosper RTTL with 2 480 motors and they give a very nice scale speed.
Dave.
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Stan

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Re: Belt drive electric motor in 70cm fishing boat
« Reply #7 on: December 04, 2018, 06:20:00 pm »

Hi Hurric 123 nice to speak to you today. S H G do offer a good range of products they are excellent to deal with and will answer all your questions. The 10 tooth pulleys will be fine just like having direct drive but via belt drive. A 385 motor will be fine for this size of model after all you are operating a speed boat.




Stan. :-)) :-)) :-)) :-))
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Hurric123

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Re: Belt drive electric motor in 70cm fishing boat
« Reply #8 on: December 04, 2018, 08:55:08 pm »

Thanks all for your suggestions. I have just looked at SHG online and I think I can source what I need from there?
The current parts fitted are:-
Motor, Mabuchi Motor RS54K ,can is 35mm d x 50mm L, shaft size 3.45mm d, and fitted with a approx 15 tooth gear.
Shaft is 3.45 mm d, fitted with approx 32 tooth gear.
Prop is 45 mm two blade brass
Battery in 7.2v NImh 2500 mah.


My only other option is to make up a full adjustable motor mount with a thinner base so that I can get the motor shaft lower into the shaft gear using elongated motor mounting holes. That way I can check out the existing gears again and get the teeth meshing really nicely to see if I can live with them, and hopefully still free running if that,s possible. The hatches on this boat are so small for my big hands, Regards all.

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Colin Bishop

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Re: Belt drive electric motor in 70cm fishing boat
« Reply #9 on: December 04, 2018, 09:11:19 pm »

You could always consider suspending the motor upside down over the shaft to get a better ine up.
Colin
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